Every year, 73 million sharks are killed for their fins. Most go to make shark fin soup, a luxury dish and status symbol in some Asian cultures that can sell for $100 a bowl. Currently, 30 percent of shark and ray species are threatened with extinction.

In recent years, graphic undercover footage of the shark finning trade has helped raise public awareness of the issue. Photos and videos usually show grim images of fishermen hauling sharks up the sides of boats, slicing off the animals' fins, then letting them slide back into the ocean — and certain death. Photographer Shawn Heinrichs and partner Paul Hilton take a different approach.

"We want to create images that draw people in rather than push them away," Heinrichs tells The Picture Show.

For the past decade, the well-traveled photographers have documented shark finning in at least 25 countries. Only a handful of countries have banned the practice. Indeed, industrial shark finning operations remain extensive around the globe, as evidenced by new images from the duo.

The Picture Show caught up with Heinrichs and asked him about capturing these powerful images as part of a project sponsored by the Pew Environment Group.

The Picture Show: How did you gain access to these operations?

Shawn Heinrichs: We've been in some of hottest areas in the world. Places where military, police and fishermen are working violently against you. To get access, we worked with really good fixers. (Fixers are people who help set up contacts, translators, transportation and so on for journalists in unfamiliar locations.) Once we go in, we have a game plan, and we stick to that game plan. We're courteous but unyielding. If it starts feeling dangerous, we will casually back out before it turns into a confrontation.

Do the people on the docks and in the boats know what you're doing?

The people there have no clue where the images are going and what we are doing with them. We come up with a very good story.

We've come up with a green, yellow, red system. A green area means you can film openly with no political ramifications. Yellow areas are places that have people looking for you. In red areas, violence can be used against you. There we might use fullundercover button cameras.

What does it feel like wandering around all the fins and dead sharks?

It saddened me to know this is happening still. We're both nature enthusiasts. We love animals and documenting them. Watching them disappear is just too much to stand back and let happen. But in this case, we almost convinced ourselves the scale we'd found here was a thing of the past. What we saw on the floors and the docks was a brutal reminder that the scale is still massive.

What do you want people to take away from these images?

A lot of imagery is too graphic for public consumption. We want to capture images that folks can look at and be drawn into with curiosity first, and then let the magnitude of the situation be revealed. It sticks with you more than one graphic image that pushes you away. Look at the images; it's impossible to sustain these species with what's still happening.